UTG 3.9" Red/green single dot reflex sight. Features: - precision machined from aircraft-grade aluminum with matte black hard coat anodize - built on true strength platform, shockproof, fogproof, and rainproof - Red/green dual-color illumination to accommodate different weather/light conditions - reinforced windage & elevation adjustment for added zero retention - features a 4 MOA single dot - extra large field of view with Unlimited eye relief for fast target acquisition and even faster target transitions - complete with integral Picatinny mounting deck for quick installation out-of-the-box and guard shield for added durability and structural integrity out in the field. Specifications: - magnification: 1x - objective diameter: 34 x 25mm - eye relief: Unlimited - exit Pupil: Unlimited - click value At100 yards: 1" - length: 3.9" - material: aluminum - weight: 8.64 oz. - Parallax setting: 100 yds - batteries: AG5 X2.